Friday, May 07, 2010

Cleaning Sewage and Generating Power Using Bacteria

Fundamental discoveries by scientists have sometimes the potential to revolutionize our lives. Here is a case where fundamental discoveries by microbiologists have the potential to revolutionize sewage treatment.

Conventional sewage treatment is an energy intensive process. Here micro-organisms digest solid waste in "activated sludge". They convert organic matter into methane but leave liquid waste containing ammonium and phosphates which is again another headache. This has to be perforce removed before the water can be poured into rivers. It is calculated that this process consumes on an average of 44 watt-hours per day for each person.

Now Dr Gijis Kuenen and colleagues from Delft University of Technology in the Netherlands are developing a technique that cuts out the energy intensive processes. The key to their new process is the newly discovered anammox bacteria. These bacteria convert ammonium directly into nitrogen gas. The by-product of the process is methane. Dr Kuenen proposes to harvest this methane and use it as fuel. The process could generate 24 watt-hours per person per day. Waste water treatment plants can be made completely sustainable.

This is an ample demonstration of how small things can sometimes bring in unexpected jackpot. Tahrcountry salutes Dr Gijis Kuenen and his team.